Complete Issue in PDF - Abstracta

Bernhard Ritter 66
… cause and effect.” (B 232) 59 The connection between “alteration” and “causality” in
this conclusion is derived by means of a principle that declares it to be necessary for the
experiencing of an object. This is the first distinctive mark of transcendental arguments.
The second and third rule states “that for each transcendental proposition only a single
proof can be found,” and “that [transcendental proofs] must never be apagogic but
always ostensive.” 60 An “apagogic” proof is a proof “by refutation of the opposite”. It
starts with searching out propositions that are known to be wrong (owing to
inconsistency or other reasons), but implied by the negation of the desired conclusion. A
modus tollens refutes the antecedent proposition and yields—“by refutation of the
opposite”—the desired result. In contrast, an ostensive proof establishes its result
directly, ideally by affirmative premises. 61
The Refutation of Idealism meets the first criterion, which will become apparent
from the presentation of the argument below. In Kant’s view it certainly meets the
second criterion too, for he claims it to be “the only possible [proof]” of things outside
us. 62 But if the Refutation-argument meets the third criterion is not clear. Its underlying
argument-structure allows for two negative premises, of which only one is actually
stated. Kant presents the idealist as somebody who drops the premise that the perception
of external objects is mediate and insecure, while self-awareness as a substance in time
remains unaffected. Since the latter (that we possess self-knowledge) materially implies
the former (that we sometimes perceive external objects), the idealist encounters a
refutation of self-awareness. Dropping the denial that we perceive external objects, it
follows that the perception of external objects is a necessary condition for selfawareness.
Hence the Refutation-argument is an ostensive proof, but its force is in part
due to an apagogic proof held in position. Therefore, it may not be altogether clear if the
Refutation of Idealism is a transcendental argument, not because it falls in between
categories, but because it is too many things at once.
The argument, then, can be paraphrased in a first attempt as follows:
59
This formulation of the second analogy gives the impression that Kant attempted to derive
metaphysical claims from epistemological conditions; instead, it should actually be stated as a regulative
principle (as an instruction on how to proceed) and as an analogy (x is related to a given alteration as
cause to effect).
60
A 787/B 815; A 789/B 817. The Guyer-Wood translation prefers to set Kant’s spacing in bold type.
61
Ak. XX: 288; cf. Ak. IX: 52.
62
B XLI.